Help me find this book I read in 7th grade

[Guest Julia]

I've been searching on the internet for a few hours trying to find a book I read in the 7th grade. I'm not sure what the genre is but it was definitely leaning towards fantasy. All I remember was a boy who had a (white or bay) horse and I think the horse was taken by an old man and he went on a journey to find the horse. They end up meeting at some cliffs and the horse emerges and so does the scary old man. Does this ring any bells? It had a really strange title too.